/*******************************************************************************
 * MIT License
 *
 * Copyright (c) 2016-2016  Daniele Demichelis
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 ******************************************************************************/

package com.danidemi.obfuscatedids.core;

public class NegativeIdsObfuscator implements IdObfuscator {

    private final IdObfuscator delegate;

    public NegativeIdsObfuscator(IdObfuscator delegate) {
        this.delegate = delegate;
    }

    @Override
    public String disguise(long id) {
        long newId = id << 1;
        newId = newId < 0 ? Math.abs(newId)-1 : newId;
        return delegate.disguise(newId);
    }

    @Override
    public long decode(String disguisedId) {
        long decoded = delegate.decode(disguisedId);
        return decoded % 2 == 0 ? decoded >> 1 : -1 * ((decoded - 1) >> 1);
        //return decoded % 2 == 0 ? decoded >> 1 : -1 * ((decoded - 1) >> 1);
    }
}
